The present invention recognizes the importance of recognizing the behavior of mid-range infrared (IR) as a form of electromagnetic radiation other than x-rays, visible light, or radio waves, for example. There is no guarantee that what we see as transparent, opaque, or reflective always corresponds with the same optical properties in IR. Oftentimes materials that appear transparent in the visible range are opaque in the IR and vice versa. Whereas we see wavelengths from about 400 nm (Violet) to 700 nm (Red), most terrestrial objects radiate according to Planck's Law in the range of 2,000 nm to 130,000 nm with the range of peak emissions spanning 8,430 nm at 70.7° C./159.3° F. to 16,240 at −94.7° C./−135.8° F. Thus, the physical difference in spectrum is very large.
In the IR range of the electromagnetic spectrum, while multiple metals can be used successfully as a reflector, gold, silver, and copper are the most effective. Aluminum is frequently used because of its low cost; however, silver and aluminum both form oxides detrimental to IR reflectivity very rapidly, whereas gold and copper do not. While widely publicized that CO2 is a greenhouse gas, it is often not explained the exact mechanism by which this occurs. Additionally, it becomes a leap of perspective to realize that the same mechanism which applies to CO2 also applies to solid and liquid states of matter. Because of the large size of wavelength of mid-range infrared electromagnetic radiation, this size corresponds to harmonics of various states of different bond lengths found in organic materials. In plastics, a result of this is that relatively simple, linear polymers using a few elements like polyethylene or polypropylene are nearly transparent to IR whereas plastics including more complex, non-linear polymers using many elements like polyurethane or polyetherimide are very opaque (or absorbent). This often remains true regardless of visible appearances which, again, may differ greatly.
The present invention comprises a low density, thermally insulating multi-layered reflective insulation system. The multi-layered reflective insulation of the present invention comprises a plurality of layers, including, but not limited to, a combination of any number of the following layers disposed on each other: scattering optics, multi-layer insulation, microsphere film, and polyblend foam.
Various prior art exists in the prior art that disclose multi-layered insulating composites, but each of these have shortcoming which the present invention overcomes.
U.S. Pat. No. 4,442,165 A to Gebhardt, Joseph J., et al., entitled “Low-Density Thermally Insulating Carbon-Carbon Syntactic Foam Composite”, discloses an insulating composite comprising a syntactic foam material, pyrolytic graphite, and a boron in layer which enables the composite to reflect infrared energy.
U.S. Pat. No. 6,858,280 B2 to Allen, Mark S., et al., entitled “Microsphere Insulation Systems”, discloses microsphere insulation systems whereby particles reduce heat transfer through reflection and scattering.
U.S. Pat. No. 8,857,700 B2 to Jackson, Adam, et al., entitled “Low Temperature Method for Forming Field Joints on Undersea Pipelines”, discloses insulation layers including microspheres.
U.S. Pat. No. 8,397,765 B2 to Jackson, Peter, et al., entitled “High Temperature Resistant Insulation for Pipe”, discloses thermal foam insulation layers with micro-spheres.
U.S. Pat. No. 6,284,809 B1 to Plummer, John, et al., entitled “Thermally Insulating Syntactic Foam Composition”, discloses an insulating syntactic foam composition.
Although the above-referenced patents disclose insulation systems, the present invention provides a low density, thermally insulating multi-layered reflective insulation system that is easy to install, offers increased R-value resulting in increased insulation, and cost effective.
Certain embodiments of the invention have other steps or elements in addition to or in place of those mentioned above. The steps or element will become apparent to those skilled in the art from a reading of the following detailed description when taken with reference to the accompanying figures.